Is my second cousin a cousin of one of my parents?

Since I'm editing all these "cousin" questions, I'm going to give a detailed explanation of this.

Yes, your second cousin is a cousin of one of your parents.

Your second cousin is the child of your grandmother's or grandfather's neice or nephew. This makes your second cousin your mother's or father's first cousin once removed.

In this scenario, pretend you are Matt.

Charles and Sue are brother and sister.

Charles is Jim's father, Sue is Becky's mother.

Becky is Charles' niece, Jim is Sue's nephew.

Jim and Becky are first cousins.

Jim is Matt's father, Becky is Lisa's mother.

Matt and Lisa are second cousins.

Matt is Becky's first cousin once removed. Jim is Becky's first cousin, Matt is Jim's child, so Matt is still a first cousin to Becky, but he is "removed" or distant by one generation.

Likewise, Lisa is Jim's first cousin once removed.

If you are Matt, your second cousin Lisa, is your father Jim's first cousin once removed.

No, your second cousin would be a 'first cousin once removed' of your parents.

No, Dave, only of your father not both - unless the parents were first cousins (legal in the UK). In McGruff's example this would entail Jim marrying Becky, and then Matt and Lisa would be brother and sister. They would also be first cousin once removed to both parents, and conceivably also second cousins to each other, although the closer brother-sister relationship would preclude any chance of them marrying legally!

I answered "yes" using "cousin" in the broader sense. Your second cousin is a cousin of one of your parents, but you need to add "first" and "once removed" to accurately describe this person's exact relationship to your mother or father.

In the same sense, your first cousin is not a cousin of one of your parents. This person would be a niece or nephew of one of your parents.